DEV Community: Mauricio Panelo

Why You Should Start Using Listcomps in Python (Say no to map/filter)

Mauricio Panelo — Sun, 27 Feb 2022 07:15:45 +0000

Yesterday, I shared a quick Python tip about for-loops versus list comprehensions.

Today, I created another infographic about list comprehensions (listcomps). Listcomps provide a readable alternative to map/filter comprehensions. As you can see from the infographic, the listcomp syntax is shorter and easier to understand.

This syntax isn't limited to lists either.

You can do dict and set comprehensions too

Here's a short example of a dict comprehension:

country_codes = [
    ("United Kingdom", 44),
    ("United States", 1),
    ("Mexico", 52),
    ("Australia", 61),
]

code_to_country = {code: country for country, code in country_codes}

The tools I use to create the infographic

I use Showcode to generate the code images
- An alternative you can use https://carbon.now.sh/
I stitch everything together using Canva
I use the Dracula color palette
If you want to include free usable images, you can use unsplash.

And that's it! I encourage you to start creating your own infographic!

Thanks for reading! Let me know if you have any feedback.

An Infographic About Python List Comprehensions

Mauricio Panelo — Sat, 26 Feb 2022 04:42:00 +0000

I spent way to much time on this infographic.

The good news is I have a template for future programming tips. I predict my time spent on the next graphic will be considerably less.

My inspiration for creating this comes from Simon Høiberg's tips for JavaScript. I recommend checking out his content.

I will say that list comprehensions shouldn't be used for everything. There are cases where it's more readable to write out the for loop (e.g. nested for loops).

List comprehensions are really powerful. You can mimic filter and map expressions using a list comprehension.

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9]

# filter numbers greater than 5
x = [n for n in numbers if n > 5]

# map the numbers to a string
x = [str(n) for n in numbers]

Thanks for reading! Let me know what you think of the infographic. I appreciate any feedback.

3 Lessons I've Learned For Conducting Better Code Reviews

Mauricio Panelo — Fri, 25 Feb 2022 05:26:19 +0000

I love doing code reviews.

I'm far from the best code reviewer. So I'm always looking for ways to improve the code reviewing process for myself and my team. In the past 4 years, I've learned a lot about effective code reviewing.

Here are 3 lessons I found worth sharing:

1/ No one is above code reviews

All code changes need to go under review.

Did a senior or junior developer write the code change? It doesn't matter. Developers are humans and humans will inevitably make mistakes. Hand your code over to a fresh set of eyes. I'm confident they'll be able to catch mistakes (if any) in the code.

Here's a quote from Code Complete about the effectiveness of code reviews:

… software testing alone has limited effectiveness – the average defect detection rate is only 25 percent for unit testing, 35 percent for function testing, and 45 percent for integration testing. In contrast, the average effectiveness of design and code inspections are 55 and 60 percent.

2/ Make it a habit to participate in code reviews

Ever feel like you have nothing to contribute in a code review?

It's OK because you don't need to know everything about the code change to participate. Here are 2 tricks I use to make sure I'm an active participant:

Trick 1: Ask questions

Is there something you don't understand?
Does something need more clarification from the author?
Are you not sure if a specific change was intentional?

Submit your questions to the author. There is no shame in asking. In the worst case scenario, you learn something new. In the best case scenario, you might help the author catch a bug.

Trick 2: Celebrate wins

Give kudos to the author.

Send them a thank you note for fixing the nasty bug. Everyone enjoys a little appreciation. When someone notices my hard work, it makes my day 10x better.

Don't be afraid to celebrate the wins--big or small.

Distribute the knowledge to other team members

There was one questionable habit I had early in my career.

I always assigned the same reviewer to my code reviews. No one else. I did it because I believed that person could give me the best feedback. And I thought it was the quickest way to merge my code.

But there was one problem.

I wasn't being transparent with my team. By not assigning other team members, I wasn't giving them an opportunity to learn about my changes or review it.

I was hoarding knowledge. I was contributing to a low bus factor. Now, I assign all relevant people to the code review. The people I want feedback the most, I make to sure to assign them as mandatory reviewer.

Thanks for reading! Are there any code review lessons you've learned? Let me know in the comments or on Twitter.

The Easiest Way To Install Node.js on Linux/MacOS

Mauricio Panelo — Thu, 24 Feb 2022 06:22:20 +0000

I've been riding the learn (build) in public wave for the past month.

Here's what I've been doing:

I code or learn for an hour
Report my progress on Twitter
Push my code to GitHub for others to see

I started learning Typescript a week ago. When I started setting up my laptop for Typescript, I needed to find a way to install Node.

I found that Node Version Manager (nvm) was one of the easiest way to install Node.

Installing nvm is super easy

You find the instructions on the official repository. Run the following:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.1/install.sh | bash

Then paste the following in your profile file:

export NVM_DIR="$([ -z "${XDG_CONFIG_HOME-}" ] && printf %s "${HOME}/.nvm" || printf %s "${XDG_CONFIG_HOME}/nvm")"
[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh" # This loads nvm

If you face any issues, refer to the README.

Install Node using nvm

Installing a specific version of Node:

nvm install <SPECIFIC_NODE_VERSION>

Installing the latest LTS version:

nvm install --lts

Using the installed Node version

Switching between Node versions is simple when using nvm. This is helpful when your different Node projects use different versions.

You can choose which Node version you want to use:

nvm use <SPECIFIC_NODE_VERSION>

Conclusion

I recommend installing nvm. It simplifies the process of installing NodeJS. The bonus is having different versions of NodeJS installed.

Let me know what you think. Are there better alternatives? Suggestions?

Thank you for reading!